Localization of Endosymbionts of Bemisia tabaci (Gennadius) Using Double-Fluorescence in situ Hybridization Approach

The bacterial endosymbionts are integral to the physiology of sucking insect pests like whitefly Bemisia tabaci, as they contribute to the nutrition and fitness traits of their host insects. While the primary endosymbiont Porteira aids nutritionally, the secondary endosymbionts play additive roles such as increased fitness, thermal tolerance and host-plant plasticity. We have deployed double fluorescent in situ hybridization (FISH) technique to detect endosymbionts of B. tabaci using 16srRNA-based FISH probes targeting both primary endosymbiont, Portiera and secondary endosymbionts Rickettsia and Hamiltonella. Our results have shown that Portiera and Hamiltonella are confined in bacteriocytes with higher concentrations, whereas Rickettsia is found to have a scattered distribution pattern outside the bacteriocytes. FISH is particularly useful in understanding the colocalization pattern of the endosymbionts and their interactions in the whitefly B. tabaci.